The present invention relates to thermal printer technology, and more specifically to thermal printers using a thermal line printing head (hereinafter referred to as a "printhead") to print images on thermosensitive paper.
Compact thermal printers using thermal line printheads are well known and widely used. Occasionally, a compact thermal printer is arranged to have a thermal line printhead pressed against a rotatable platen roller. To insert thermosensitive paper, or in the case of a paper jam, the thermal line printhead can be released from the platen roller by manually operating a release lever, which directly or indirectly moves either the platen roller or the printhead away from the other.
However, with the conventional compact thermal printer, the rotating axes of the release levers and associated mounting parts are, in most cases, located near the paper discharge slots. The paper discharge slot is often located in a lower portion of the printer's external casing, far from the rotating axis of the released part. This leads to the necessity for a strong release lever, or expanding the paper discharge slot. The conventional arrangement thereby renders paper insertion or jammed sheet removal operation inconvenient, and often results in an unwieldy structure. The salient problem is that conventional arrangements of insertion and discharge slots, release levers, printer housings, and printer covers are unsatisfactory for an extremely compact printer. It is therefore desirable to combine some of or all of the functions of the above-mentioned structural elements together.
Further, if the thermal line printhead sticks to the platen roller, the conventional paper release action may not always allow the thermal line printhead to separate from the platen roller the printer may therefore have unsatisfactory reliability. It is therefore desirable to be able to release the thermal line printhead from the platen roller.